Stencil printing apparatus



Sept. 15, 1936. H. P. ELLIOTT STENCIL PRINTING APPARATUS Filed July 28, 1934 6 Sheets-Sheet 1 15, 1936; P EL' STENCIL PRINTING APPARATUS Filed July 28, 1934 6 Sheets-Sheet 2 Sept. 15, 1936.

H. P. ELLIOTT STENCIL PRINTING APPARATUS Filed July 28, 1954 6 Sheets-Sheet 3 ATTEIRHEL:

Sept. 15, 1936., H. P. ELLIOTT STENCIL PRINTING APPARATUS 6 Sheets-Sheet 4v Filed July 28, 1954 d m m m m m m m a mm m n m m m m a m a m m m m m m .m m m m m m m m Q m m in; D

. m m m m m m m D m m m D m m m m m m. m m m m m mw Gunman m m m m m E H. P. ELLIOTT STENCIL PRINTING APPARATUS Sept. 15, 1936.

Filed July 2s, 1934 .6 Sheets-Sheet 5 A TDF'KHEH:

Filed July 28, 1954 6 Shegts-Sheet 6 7 ATTmRNEq Patented Sept. 15, 1936 PATENT OFFICE STENCIL PRINTING APPARATUS Harmon P. Elliott, Watertown, Mass., assignor to Elliott Addressing Machine Company, Cambridge, Mass., a corporation of Massachusetts Application July 28, 1934, Serial No. 737,336 3 Claims. (01. 101-50) It has been the special object of my invention to create an apparatus which shall permit the automatic, unlimited repetition of a cycle of operation upon a group of stencils, so that a series of printed elements, such as cards or paper sheets, may be repeatedly reproduced, by stencil printing, in the same order of reproduction and. without the necessity of manually reassembling and restacking the separate stencils and placing them again and again in feeding position in the machine according to the long established practice.

This I have accomplished by organizing a group of stencils into a flexible, endless strip and providing means to bring each of the individual stencil elements forming the strip into repeated engagement with a card, sheet or other element to be printed upon, and to bring the stencil element and card into joint cooperative relationship with the printing means. The result is to afford to the stencil printing art, which is so capable of practice by unskilled operators, a device which shall perform the automatic continuous reproduction of a series of printed cards or sheets in a rapid and convenient manner.

In the following described machine in which I have incorporated the above mentioned endless flexible strip composed of individual stencil elements, I have embodied several features already old and well known in the stencil printing art and in some instances described and shown in patents which I shall hereinafter mention.

My device may be best understood by reference to the accompanying drawings in which- Fig. l is a front elevation of a preferred type of stencil printing machine having my improvements embodied therein.

Fig. 2 is a medial longitudinal sectional view of the entire machine.

Fig. 3 is an enlarged top view of the clutch by means of which the motor driving power is transferred to the printing mechanism and other moving parts of the machine. 7

Fig. 4 is an enlarged front view of the driving gear and accompanying clutch engagement elements mounted in the hub thereof.

Fig. 4a is a sectional view on line 3-3 of Fig. 3 showing the face of the hub of the fixed element of the clutch mechanism with its inset dogs for clutch engagement.

Fig. 5 is asectional view on line 5--5 of Fig. 3 showing the clutch release bar in the operative position.

Fig. 6 is a cross section on line 66 of Fig. 5 showing the conformation of the operative end of the clutch release bar.

Fig. 7 is an enlarged transverse View showing the arrangement of the stencil strip actuating sprocket roller and associated upper and lower rollers for holding the strip in engagement with the sprocket roller, and also the conveyer for 5 spreading out and removing from the machine printed cards or sheets, together with the mechanism for actuating the said conveyer. V

Fig. 8 is an enlarged top view of the stencil strip and actuating parts shown in Fig. '7 with a stencil strip in operative engagement therewith.

Fig. 9 shows an individual stencil element.

Fig. 10 is an enlarged rear view of the ink distributing and printing rollers, showing, in medial longitudinal section, the front end and outlet control means of the card or sheet feed hopper and adjacent card or sheet forwarding and guiding means.

Fig. 11 is a view on line l|-H of Fig. 10showing the assemblage of inking and printing rollers 0 and their actuating and control parts.

Referring now more specifically to the drawings, in which like reference numbers indicate like parts, I is a platform or table supported by legs 2. Mounted on the top of the table by means of legs 3 is the mm'n machine frame 4 which is provided with opposite upward extensions 5 and 6 (see Fig. 11) Mounted beneath the platform I is an electric motor 1, the driving shaft 8 of which is attached by the coupling9 to the shaft ID of a suitable reduction gear mechanism II which is bolted to the under side of the platform I. The reduction gear mechanism l I has a transverse shaft l2 which has fixed thereon a pulley 13 having an enlarged hub l4 carrying dogs l5 arranged normally to contact with a cylindrical pin l6 pocketed in hole I! in the hub l8 on a sprocket gear 19 which is loose on the shaft l2. The cylindrical pin I6 is normally thrust outwardly against the end of the hub l4, so that it may engage a dog I5, by the coil spring 20 pocketed in the base of the cylindrical hole I l. The hub l8 has a deep annular channel 2| and the pin l6 has a reduced portion 22 into which may enter the wedge shaped end 23 of the clutch operating arm 24 which, when in the position shown in Fig. 5, will, upon the rotation of the sprocket gear l9, engage the rearward shoulder of the larger part of the pin l6 and, upon the continued rotation of the gear l9, force the retirement of the pin it so as to prevent the driving engagement of a dog l5 therewith.

The clutch operating control arm 24 is normally supported in an elevated position so as to cause clutch'release by a cam roller 25 operated by the control lever 26, which will, when moved forward, permit the arm 24 to drop, swinging on its pivot 30, thereby causing clutch engagement. A coil spring 21 attached at its top to the clutch operating control arm 24 and at its lower end to a bracket 28 depends from the plaform and keeps the clutch control arm 24 in firm engagement with the cam roller 25.

The pulley 3 carries a flexible endless belt 3| the upper end of which passes about a driving pulley 32 fixed on the end of a shaft 33 transversely and rotatably mounted in the frame extension sides 5 and 6 (see Figsl and 11). Theshaft 33 has fixed thereto a rubber faced ink distributing roller 34, which is rotating at all times when the driving motor is in operation.

The sprocket gear l9 on the shaft 12 carries a sprocket chain 35 which passes about a sprocket gear 36 attached to a rotatable shaft 31 mounted transversely in the frame 4 (see Fig. 11) The rotatable shaft 31 has also fixed thereon a segmental inkingroller 38 and a gear 31a which meshes with a gear 311) fixed on the rotatable shaft 310 on which is fixed a segmental platen roller 42 which underlies and cooperates with the segmental inking roller 38.

As means for supplying ink to the segmental inking roller 38 I have provided the roller shaped ink reservoir 39 with small holes 40 on a limited portionof its periphery. This ink reservoir 39 is rotatably mounted on trunnion pins 4| which are eccentrically disposed in hubs 4|a. which are connected by the yoke 43, and which are loosely and rotatably supported in the forked extremities 44 and 45 of the frame extensions 5 and 6 respectively. The thumb piece 46 is attached to one of the hubs 4|a so that the operator may conveniently give a partial rotation to the hubs 4|a. thereby causing the ink reservoir roller 39, because of its eccentric mounting, to be pressed into engagement with the rubber faced roller 34 on the shaft 33. When the operator releases the thumb piece 46 the weight of the yoke 43 will cause the ink reservoir roller 39, upon the partial rotation ofthe hubs 4|a, to be raised out of contact with the roller 34. The ink reservoir roller 39 is weighted internally on its inner periphery so as to cause it to rotate automatically sufficiently to bring the ink dispersing holes therein above the liquid level of the ink when it is lifted out of contact with the roller 34. Such an inking device is generally described and claimed in my Letters Patent of the United States, No. 1,614,547, dated January 18, 1927.

Beneath the intermediate inking roller 34 is mounted a pair of felt faced ink absorbent rollers.48 (see Figs. 10 and 11). These rollers 48 are mounted upon a frame 49' by means of shafts 50 which extend between opposite ends of the frame 49 which is centrally mounted on a cross shaft 5| which is rotatably supported between the sides 5 and 6 of the frame extension. The frame 49 carries an upwardlyextending arm 52 upon which is loosely pivoted at one end the connecting rod 53, the other end of which is eccentrically pivotedon a gear 54 rotatably mounted 'ona bracket 55 fixed to the side of the frame 5. The gear 54 meshes with a worm gear 56 fixed on the shaft 33 so that upon rotation of shaft 33 the gears 56 and 54 will rotate thereby causingthe connecting rod 53 to reciprocate the frame 49 and the rollers 48 thereon mounted, so as to. cause a wiping contact between the rollers 48 and rollers with which they engage, soasbetter to spread the ink. The shaft 5| is provided with a slot or groove on its end surface which is entered loosely by a pin 51 extending through the central portion of the frame 49 so that the angular position of the shaft 5|, upon being set by the crank 58, which is under the eccentric tension of spring 59, will cause one or the other of the felt faced rollers 48 to contact with the intermediate inking roller 34 while its opposite roller 48 bears upon the lower rubber faced intermediate inking roller 60 which is freely rotatable upon a cross shaft 6| mounted between the sides of the frame extensions 5 and 6. The lower end of the spring 59 loosely embraces the end of the shaft 6|. The shaft 6| has a reduced and slightly eccentric portion 62 on which the roller 66 is mounted and the reduced end enters in an eccentric position an annular .hub63 which is fixed on the reduced end portion 62 of the shaft 6|, the hub 63 being concentric with the shaft 6|, so that a partial rotation of the hand wheel 64 will cause the roller 60 to be slightly elevated and removed from contact with the rubber faced segmental roller 38, an operation which is desirable if the machine is to be left idle for a substantial period of time since otherwise the contacting surfaces of rollers 60 and 38 might become flattened or distorted so as to impair the effectiveness thereof.

A sprocket gear 61 fixed on the shaft 31 is con nected by the sprocket chain 68 with a sprocket gear 69 fixed on the shaft 10 which is rotatably mounted between brackets 40. mounted on the base of the frame 4 (see Figs. 1, 7, and 8). The shaft 16 has fixed thereon a sprocket roller provided with parallel rows of sprocket teeth 12 spaced to engage the symmetrically spaced perforations l3 along-the edges of a stencil strip 14, which stencil strip is arranged to form an endless belt supported by a curved elevated guideway 15 provided with flanges 16, the guideway 15 being supported by arms I1 and 18 extending upwardly from the frame extension 6. The end of the loop formed to the right of the stencil strip feed sprocket roller after passing over the curved guideway 15 is positioned by a curved guideway 19 so that it will pass between the segmental rollers 38 and 42 before passing again into engagement with the sprocket roller II and continue to the left to form a loop as shown in Figs. 1 and -2 which loop may bear against one or both of the idler rollers and 8| mounted between parallel spaced posts 82 mounted upon the platform I.

V The endless strip of stencil units, organized as above described, is formed of separate elements or units, as shown in Fig. 9, which are provided with a frame 83 made preferably of a strong but flexible paper and provided with a window or opening 84 which is covered by a thin strip of coated tissue paper, such as the well known Yoshimo paper commonly employed for making coated tissue paper stencils of the well known type provided with a coating which may be written or drawn upon by a stylus or written upon by a typewriter, so that the stencil becomes pervious to ink where the ink impervious coating has been cut through by the stylus or by type of the typewriting machine. Of course, each stencil is prepared for use, by writing or drawing thereon, before the separate units are assembled into the strip 14 which is preferably done by the use of thin, short wire clips or staples 85 which may be readily attached by any one of several well known machines or hand devices now commonly in use for attaching together sheets of paper;

The upper and lower parts of the endless stencil strip 14 are maintained in firm driving engagementwith the sprocket roller H by means of upper and lower pairs of yieldably mounted clamping rollers 86 which have annular reduced portions 81 to permit the passage of the sprocket teeth 12 upon the roller H. The upper pair of clamping rollers 86 is mounted upon and between a pair of bracket plates 88 (see Figs. '7 and 8) each of which is slidably supported upon one of the outer faces of the opposite sides of brackets 4a and yieldably held downward by a coil spring attached at its upper end to a pin 9I attached to a bracket plate 88 and at its lower end to a pin 92 attached to the adjacent side of a bracket 4a and passing through a slot 93 in the bracket plate 88. The lower pair of clamping rollers 86 is yieldably held upward against the sprocket roller 1I by the pull of spring 84 attached at its top to the frame 4 and at its lower end to a bar (see Fig. 1) which is a part of a frame 86 having forked extensions 91 in which are journaled the lower pair of clamping rollers 86. The bar or member 95 of the frame 96 is pivoted by a pivot 98 upon a post 99 attached to the frame 4. It may be readily understood that this yieldable mounting of the clamping rollers is for the purpose of permitting an end of the stencil strip 14 to be threaded into engagement with the roller H and led over the guideway 15 and around the guideway 19 and through the opening between the segmental rollers 38 and 42 and thence beneath the sprocket roller '1I, before the ends of the strip 14 are joined together to form a continuous belt or strip which has a loop embracing the idler rollers 80 and 8|. .A feed roller or drum IOI for feeding the cards or sheets to be printed upon is fixed upon a shaft I02 rotatably mounted between the sides of the frame 4. The larger part: of the periphery of the drum I M is smooth but it bears upon a limited part of its periphery a corrugated rubber friction plate I03. The shaft I02 of the feed drum IOI has attached thereto a sprocket gear I04 about which passes a sprocket chain I05 which engages a similar sized sprocket gear I06 (see Fig. ll) which is fixedly mounted on the shaft 4I supporting the lower segmental roller 42 so that power taken from the shaft 4I may drive the feed drum MI. The shaft I02 also has fixed thereon a pulley I81 which carries a belt I08 which engages a pulley I09 (see Figs. 1 and 10) fixed to a shaft IIO rotatably mounted between the sides of the frame 4, which pulley I09 has attached thereto and rotatable therewith a feed roller III. The upper part of the periphery of the feed roller I I I extends through a slot I I2 to a height slightly above the top of a transverse feed bed H3 in the frame 4.

Mounted on the frame 4 above the feed drum IOI is a feed hopper II4 having side walls H5 and a front wall II6 (see Figs. 1 and 10) which feed hopper is of a general type now long in use, the base II 1 of which supports only the rearward part of the stock of cards or sheets II8 placed therein, the lowermost card resting at its front part on the top of the drum I M so that the lowermost cards may successively be fed forward one at a time, by engagement of the corrugated rubber strip I03 upon the periphery of the drum IOI, through the opening beneath the stop blade II9 which is slidably held against the adjacent rear face of an inset portion I20 of 'in the rod I49.

the front wall H6. The stop blade II9 is retained in position by screws I2I which pass through slots I22 in the inset portion I20 of the front wall I I6 and through spring plates I23 and I24 and stiff plate I25 and the adjusting bar I26, the position of which bar is controlled by a screw I21 having a knurled thumb-nut I28, which screw I21 passes through a threaded block I29 attached to the front face of the top part of the front wall H6. The lower end of the adjusting screw I21 passes freely through a hole'in the bent-over top I 30'of the adjusting bar I26 and is engaged in fixed but rotatable relation with the adjusting bar I26 by means of collars I3I and I32 which are fixed on said adjusting screw Above the feed roller III is an idler roller I 34 which is mounted between the sides of a bracket I35, the back of which is clamped between the lower extremities of the spring plates I 23 and I24. A presser plate I36 has a forked rearward extremity which straddles the roller I34 and is pivotally mounted on a pin I31 which extends between the sides of the bracket I35. The forward endsof each side of the bracket I35 rest upon the top of the'presser plate I36 and thus the presser plate I36 and the idler roller I34 are normally forced downward under the tension of the spring plates'I23 and I24 so as to hold an advancing card from the stack I-I8 firmly against the feed roller II I and the feed bed II 3.

A belt conveyer I40 (see Figs. 1, 2, and 7) for spreading out and removing from the machine the printed cards or sheets, is mounted upon rollers HI and I42 journaled at opposite ends of a frame I43, which frame is supported on legs I44 attached to the platform I. The shaft I42a to which is fixed the roller I42 has attached thereto a ratchet-wheel I45 engaged by a pawl I45 pivoted in a link I41, which pawl I46 is held against the ratchet-wheel I 45 by the spring I 48. The movable end of the link I41 is give'n'reciprocating action by the loosely, pivotally connected rod I49, which is slidably mounted on a post 4b which is attached to the frame 4, by means of the large heads of pins I50, which pass freely through slots The rod I49 bears upon and is actuated by a cam I5I fixed upon the shaft 10, being held in yielding contact therewith by the coil spring I52, the upper end of which is attached toa pin I53 attached to the frame 4, and the lower end of which is attached to a pin I54 which passes through a slot I55 in the post 41)- and is fixed in the rod I49.

A sprocket chain supporting wheel I6!) is mounted on a bracket I6I adjustably fixed on the frame 4 by means of screws I62 which pass through slots in the bracket I6I. A stop plate I63 is mounted on a bracket I64 attached to the frame and serves to intercept the printed cards as they are projected from between the segmental rollers 38 and 42 and cause them to fall upon the conveyer belt I40.

From the foregoing description the general operation of my device may be readily understood. It is to be understood, however, thatprior to operation the position of the stencil strip 14 is so adjusted, by engagement with the sprocket roller II, that an individual stencil will be engaged by the advancing edge of the segmental printing roller 38, as it rotates with clockwise motion, at a point closely adjacent to the advanced edge of the thin stencil sheet covering the'window 84. Then as the rotation of thev segmental roller 38 continues it will press down upon the entire extent of the thin stencil. paper covering the window 84 since the peripheral length of the segmental roller 38 coincides substantially with the length of thewindow opening 84', and, during the interval whenthe segmental printing roller 38 is not in engagement with the stencil strip, the stencil strip will advance sufficiently under the influence of the feed roller II, to bring the next succeeding unit of the stencil strip into correct printing alignment with the segmental printing roller 38, the cut-away portions of the peripheries of the segmental rollers 38 and 42 being sufficient. to permit this. It is to be noted that the roller H and. the segmental rollers 38 and 42 have the same gearing and substantially identical peripheral speeds. The segmental platen roller 42, revolving in identically timed relation with the segmental printing roller 38, but in the opposite direction, will support each card to be printed, as the cards are successively advanced into printing position beneath the stencil strip 14. The position of the feed roller Ill with respect to the cooperating segmental rollers 38 and 42 is such that when a card or sheet from the feed hopper H4 advances beyond the influence of the feed roller H I it is immediately brought to a stop, by the frictional drag of: the presser plate I36, in correct position for proper registration with the overlying stencil unit through which it receives an imprint. As the gearing is such that the feed drum Ifll makes one revolution for each revolution of the segmental rollers 38 and" 42 and the feed roller H, which actuates the stencil strip, a card or sheet is advanced from the feed hopper I !4, through the influence of the friction strip N13, to meet each individual stencil as it is advanced under the segmental printing roller 38.

As the cards or sheets which have been printed upon pass from under the influence of the cooperating segmental rollers 38 and dZnthey are projected against the stop member I63- and fall" upon the top of the conveyer belt I40 which is given successive intermittent movements toward the roller Ml through the action of the cam (5! upon the rod I49 and the pawl-bearing link'Jfl, the pawl I46: of which engages the ratchet wheel M5. Hence the printed cards or sheets arefanned out upon the top of the belt conveyer I40 and, by placing any convenient marking devices upon the belt conveyer I40 to indicate the beginning and end of a cycle of printing operations, the operator may remove from the belt, from time to time, complete sets of the printed cards and thus keep the printing operations uninterrupted, as the operator may, in intervals between the removal of sets of printed cards, from time to time, replenish the stack of cards in the feed hopper H4.

It is obvious that many ways may be devised for supporting the endless strip of stencils but it is preferable to do so with as few abrupt changes of direction as possible in order that there may be a minimum frictional drag upon the rather frail paperstructure of the stencil frames 82', and consequently I find my particular means of mounting and supporting the endless stencil strip, whereby that part thereof which lies to one side of its feed sprocket roller H passes over the curving guideway 15, is very advantageous since the. curved guideway 15 may be adjustably mounted in a considerably more elevated position if it is desired to deal with a larger endless stencil strip; and, moreover, that part of the stencilstrip 14 which liesin a loop to the other side of the, feed sprocket roller :H may be considerably lengthened without any change in the structure of the machine so that my device may readily accommodate endless stencil strips of varying length. r

It is, moreover/to be noted that since the stencil strip is in feeding engagement with opposite parts of the periphery of the sprocket roller II the loop thereof which passes over the curved guideway [5 and around the curved guide plate 19 is kept constant in extent and maybe set in rather loose relationship with these elements so that there isno heavy frictional drag'thereon, either because of the actuating force of the sprocket roller H or the influence of the cooperating printing and platen rollersv since these rollershave substantially the same peripheral speed as that of the sprocket. roller H which keeps the stencil strip in continuous movement. It will be observed, therefore, that the relatively free loops of the stencil strip-lying to either side of the sprocket roller H are supported and moved with a minimum of stress upon the rather fragile structure of the stencil strip, which is, of course, very important.

The particular means which I have shown for stacking and forwarding the cards or sheets to be printedv upon is substantially that described and claimed in my Letters Patent No. 1,694,619, dated December: 11, 1928, for addressing machines'and I havealso employed in my machine herein described means for printing upon the cards or sheets through a superimposed stencil passing, withthe card or sheet, between segmental rollers embodying; features described and claimed in my Patent No. 1,908,910 of May 16, 1933, which patented devices, however, deal with stencils fed for- V ward intermittently from a stack into cooperative relationship with the card, sheet or envelope to be printed upon.

It will be readily understood that there may be many changes in the details of structure and mode of operation of my device without departing from its broad principle of providing, as a stencil means, a continuous strip of flexible stencil elements, and associating therewith means for feeding cards successively into printing position with respect to individual stencil units and means for printing upon 'said' cards through said stencil units. Of course I do not limit myself to stencils of the coated tissue paper type as any other type of stencil unit might serve.

Having thus fully described my invention, what I claim is-- v 1. In a device of the character specified, the combination of an endless stencil strip made up of a group of individual stencil units and provided with perforations for engagement by actuating means, a. sprocket roller provided with teeth for engaging said strip through said perforations for actuating the same, a printing roller, a platen 0 roller and between said printing. and said platen o5 rollers, said supporting and guiding means comprising a first curved plate located above said ink supplying means and said printing roller and a second curved plate located and arranged so as to direct said strip between said printing and platen 70 rollers, and means for'feeding sheets to be printed upon by said individual stencil units successively into engagement with said strip, in a manner whereby each of said sheets may register with a single stencil. unit, successive sheets registering with successive stencil units as said sheet and stencil unit pass between said rollers.

2. In a device of the character specified, the combination of an endless stencil strip made up of a group of individual stencil units and provided with perforations for engagement by actuating means, a sprocket roller provided with teeth for engaging said strip through said perforations for actuating the same, means for retaining said stencil strip in engagement with opposite parts of the periphery of said sprocket roller in a manner whereby loops are formed by said stencil strip to each side of said sprocket roller, a printing roller, a platen roller arranged to cooperate with said printing roller, means for supplying ink to said printing roller, means for supporting the loop formed by said stencil strip to one side of said sprocket roller and guiding the same above said printing roller and said means for supplying ink to the same and between said printing and platen rollers, and means for feeding sheets to be printed upon by said individual stencil units successively into engagement with said strip, in a manner whereby each of said sheets may register with a single stencil unit, successive sheets registering with successive stencil units as said sheets and stencil units pass between said rollers.

3. In a device of the character specified, the combination of an endless stencil strip made up of a group of individual stencil units and provided with perforations for engagement by actuating means, a sprocket roller provided with teeth for engaging said strip through said perforations for actuating the same, means for retaining said stencil strip in engagement with opposite parts of the periphery of said sprocket roller in a manner whereby loops are formed by said stencil strip to each side of said sprocket roller, a printing roller, a platen roller arranged to cooperate with said printing roller, means for supplying ink to said printing roller, means for supporting the loop formed by said stencil strip to one side of said sprocket roller and guiding the same above said printing roller and said means for supplying ink to the same and between said printing and platen rollers, means for actuating said sprocket roller and said printing and platen rollers in a manner whereby their respective peripheral speeds may be substantially the same, and means for feeding sheets to be printed upon by said individual stencil units successively into engagement with said strip, in a manner whereby each of said sheets may register with a single stencil unit, successive sheets registering with successive stencil units as said sheets and stencil units pass between said rollers.

HARMON P. ELLIOTT. 

